package com.excilys.capiq.server;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA1Helper {

	private static String convertToHex(byte[] data) {
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < data.length; i++) {
			int halfbyte = data[i] >>> 4 & 0x0F;
			int two_halfs = 0;
			do {
				if (0 <= halfbyte && halfbyte <= 9) {
					buf.append((char) ('0' + halfbyte));
				} else {
					buf.append((char) ('a' + (halfbyte - 10)));
				}
				halfbyte = data[i] & 0x0F;
			} while (two_halfs++ < 1);
		}
		return buf.toString();
	}

	public static String hash(String text) {
		MessageDigest md;
		try {
			md = MessageDigest.getInstance("SHA-1");

			byte[] sha1hash = new byte[40];
			md.update(text.getBytes("iso-8859-1"), 0, text.length());

			sha1hash = md.digest();
			return convertToHex(sha1hash);
		} catch (NoSuchAlgorithmException e) {
			throw new RuntimeException(e);
		} catch (UnsupportedEncodingException e) {
			throw new RuntimeException(e);
		}
	}

	public static void main(String[] args) {
		String password = "";
		System.out.println(hash(password));
	}
}
